How do you adjust contrast in pdfs?

[jshzh]

Texts in some text-based pdf files are not black enough to be read comfortably. How do you darken the texts in Pocketbook pro?

I could only change the width of strokes with ADOBE PRO one page per time. The result is great but very time consuming for BOOKS. I also tried to convert PDF files into Word and then adjust fonts to bold. But it would change the format of the text. If then I adjusted the margins in Word, it created blank space on many pages -- even within one sentence.

I didn't realize the pdf contrast issue was so important. Unfortunately PB programmers are not working on it. It makes me think about getting a Sony PRS-650

[skydive]

Unfortunately NO, You can not. The only thing as a workaround is landscape mode and zoom. Sorry!

Originally Posted by jshzh

Texts in some text-based pdf files are not black enough to be read comfortably. How do you darken the texts in Pocketbook pro?

I could only change the width of strokes with ADOBE PRO one page per time. The result is great but very time consuming for BOOKS. I also tried to convert PDF files into Word and then adjust fonts to bold. But it would change the format of the text. If then I adjusted the margins in Word, it created blank space on many pages -- even within one sentence.

I didn't realize the pdf contrast issue was so important. Unfortunately PB programmers are not working on it. It makes me think about getting a Sony PRS-650

[troll05]

Originally Posted by jshzh

It makes me think about getting a Sony PRS-650

Go into a Sony shop and give it a fair comparison with your Pocketbook
The PRS350 of my wife does it not much better than my 602. I don't know what exactly they do with this contrast option, but IMO it darkens only the complete system which makes it a bit more pleasantly to read in bright light, but it's not what I'd call a real contrast enhancer

[jshzh]

Originally Posted by troll05

Go into a Sony shop and give it a fair comparison with your Pocketbook
The PRS350 of my wife does it not much better than my 602. I don't know what exactly they do with this contrast option, but IMO it darkens only the complete system which makes it a bit more pleasantly to read in bright light, but it's not what I'd call a real contrast enhancer

Really? I know there is no way to brighten the "white" background but...

I was about to order a refurbished one from Bestbuy today but they just raised the price from 190 to 200...Although I can still return it within 2 weeks, I just loathe this kind of price-raising.

How does the Kindle "darkening" function work? The same way?

I really love the result of wider strokes done with Adobe Pro but I can't find a way to set the stroke width of the entire book at once..

[rkomar]

Originally Posted by jshzh

I really love the result of wider strokes done with Adoce Pro but I can't find a way to set the stroke width of the entire book at once..

Try changing just one page, comparing the new file to the original, and seeing if it's a simple change that can be performed with a search-and-replace script on the whole file. Pick a page right near the beginning so the difference shows up as soon as possible. Maybe you'll be lucky and the script will be easy to write.

[paola]

Originally Posted by jshzh

Texts in some text-based pdf files are not black enough to be read comfortably. How do you darken the texts in Pocketbook pro?

I could only change the width of strokes with ADOBE PRO one page per time. The result is great but very time consuming for BOOKS. I also tried to convert PDF files into Word and then adjust fonts to bold. But it would change the format of the text. If then I adjusted the margins in Word, it created blank space on many pages -- even within one sentence.

I didn't realize the pdf contrast issue was so important. Unfortunately PB programmers are not working on it. It makes me think about getting a Sony PRS-650

if you have Adobe Pro, you could try this: go into Edit\preferences\accessibility. There are various options on enhanced contrast there that you could try (including changing the document to white on black).

EDIT: you could make the changes even with acrobat Reader, but you wouldn't be able to save the changed file.

[jshzh]

Originally Posted by rkomar

Try changing just one page, comparing the new file to the original, and seeing if it's a simple change that can be performed with a search-and-replace script on the whole file. Pick a page right near the beginning so the difference shows up as soon as possible. Maybe you'll be lucky and the script will be easy to write.

Thanks. What do you mean by "search-and-replace script"? I couldn't find that option in the tools. I could search for words but not scripts. Please advise.

[rkomar]

Originally Posted by jshzh

Thanks. What do you mean by "search-and-replace script"? I couldn't find that option in the tools. I could search for words but not scripts. Please advise.

I meant to write a script (batch file under Windows) that runs on the shell command-line using something like 'sed' under Unix or Cygwin. I wasn't talking about options within Adobe Pro itself. If you're not experienced with writing scripts, then I would forget about it. It wouldn't be worth the effort of learning all that just for this, when something like paola's suggestion would be easier for you.

[jshzh]

Originally Posted by paola

if you have Adobe Pro, you could try this: go into Edit\preferences\accessibility. There are various options on enhanced contrast there that you could try (including changing the document to white on black).

EDIT: you could make the changes even with acrobat Reader, but you wouldn't be able to save the changed file.

I just tried with Adobe Pro 9 Extended, paola, black on white, white on white, and yellow on black...But they all display exactly the same contrast on Adobeviewer. It is a colored text. On computer screen there are only two colors (my new setting) but on PB there are still three colors, the original black is grey, the colored text is light grey, and the greyish screen...White on black displays the same way as black on white.

Maybe because the Adobeviewer has 16 scales of grey? The only way works for me so far is to change the stroke width.

[paola]

I am sorry it did not work (for my files I can't even use the stroke option, as it looks nasty - I would really have to change the font, but for long documents it's a nightmare, as you have to go page by page, as I am sure you know).
Hopefully rkomar's solution is going to work!

[jshzh]

Originally Posted by paola

I am sorry it did not work (for my files I can't even use the stroke option, as it looks nasty - I would really have to change the font, but for long documents it's a nightmare, as you have to go page by page, as I am sure you know).
Hopefully rkomar's solution is going to work!

Yes, PAGE BY PAGE.

If djvuViewer could be modified for darker text display, I guess Adobeviewer could be modified too. It might be very easy. But apparently Pocketbook company is not doing it now.

Unfortunately, I don't know how to write script at all. Thanks, rkomar. I only know how to complain LOL

[jshzh]

New discovery:
When use http://any2djvu.djvuzone.org/ , lower the resolution I set, the darker/thicker output djvu I get. It takes 15 mins to convert a very complicated (many colors, fonts, symbols) 1000 page pdf file into djvu...But it is better than manual work and the result is satisfying. And you can keep the original page layout.

[rkomar]

Originally Posted by jshzh

New discovery:
When use http://any2djvu.djvuzone.org/ , lower the resolution I set, the darker/thicker output djvu I get. It takes 15 mins to convert a very complicated (many colors, fonts, symbols) 1000 page pdf file into djvu...But it is better than manual work and the result is satisfying. And you can keep the original page layout.

I can see how that works, since you are converting the PDF to images. Does it still keep the text information, i.e. can you still search for text inside the document?

[jshzh]

Originally Posted by rkomar

I can see how that works, since you are converting the PDF to images. Does it still keep the text information, i.e. can you still search for text inside the document?

No. I first converted a Chinese file which I cannot search anyways since there is no way to input Chinese on PB. There are programs that can keep the file searchable -- I heard.

And this method only works for some files. I converted another much simpler file but the text in Djviewer is as light as that in AdobeViewer. :-(